import java.util.Scanner;

public class Exercises7{
  public static void main (String[] args){

    Scanner sc = new Scanner(System.in);

    int sum = 0;
    String str = sc.next();
    String[] strs = str.split("", 0);

    for(int n = 0; n < strs.length; n++){
      // boolean flag = isNumber(strs[n]);
      if (isNumber(strs[n])){
        int num = Integer.parseInt(strs[n]);
        sum += num;
      }
    }

     System.out.println(sum);
  }

  public static boolean isNumber(String num){
    try{
      int n = Integer.parseInt(num);
      return true;
    }catch (NumberFormatException e){
      return false;
    }
  }
}